Electric circuit breaker having remotely operable contact arm carrier latching means

ABSTRACT

Latching means for holding the movable contact arm carriers of a multipole molded-case electric circuit breaker in an open or OFF position while the operating handle is held in an ON position. The latching means is electrically operable from a remote point to release the contact arm carriers and allow them to move to ON position toward which they are biased by a spring of a toggle mechanism when the operating handle is in ON position.

United States Patent Inventors Appl. No.

Filed Patented Assignee ELECTRIC CIRCUIT BREAKER HAVING REMOTELY OPERABLE CONTACT ARM I 501' Field otSearch [56] References Cited I UNITED STATES PATENTS 2,754,389 7/1956 Yarrick 335/10 3,273,089 9/1966 Franz 335/166 Primary ExaminerHar0ld Broome Anorneys-Harold .I. Rathbun and Paul .1. Rose ABSTRACT: Latching means for holding the movable contact arm carriers of a multipole molded case electric circuit breaker in an open or OFF position while the operating handle GARNER F EF MEANS is held in an ON position. The latching means is electrically 4 Chums 8 Drama; I operable from a remote point to release the contact arm car- U.S. Cl 335/8, riers and allow them to move to ON position toward which 335/167 they are biased by a spring of a toggle mechanism when the Int. Cl I-I0lh 77/00 operating handle is in ON position.

2o\ 26 ON m -40 O F 14 PATENIEU AUG24 nan SHEET 1 [IF 3 OFF //VVE/V7 0/?$ ROBERT E. DIETZ BERYL W LAYTON FIG I ATTORNEY ELECTRIC CIRCUIT BREAKER HAVING REMOTELY OPERABLE CONTACT ARM CARRIER LATCIIING MEANS The latching means of this invention is useful particularly with circuit breakers of the type disclosed in copending application, Ser. No. 776,608, filed on Nov. l8, I968, now US.

each of the three carriers carrying an arcing contact arm 28 1 and a-pair'of main contact arms 30.

Pat. No. 3,525,837, issued Aug. 25, 1970, and assigned to the I assignee of this application.

This invention relates generally to remote control means for FIG. I is a'front view of a circuit breaker including remotely releasable latching means constructed in accordance with the invention, a portion of the cover of the circuit breaker being broken away; 7 FIG. 2 is a view of alatching device forming part of the latching means of the circuit breaker of FIG. 1, taken in the direction of arrows 2-2 of FIG. I;

FIG. 3 is a view of the latching device taken in the direction of arrows 33 of FIG. 2;

FIG. 4 is a view of the latching device taken in the direction of arrows 44 of FIG. 3;

FIG. '5 is a view of a latch member of the latching device taken in the direction of arrows 5--5 of FIG. 4; 7

FIG. 6 is a perspective view of the latch member of FIG. 5;

FIG. 7 is a view taken in the direction of arrows 77 of FIG. 1 showing a contact arm carrier and the latching device which-form the latching means of the circuit breaker; and

FIG. 8 is a sectional view taken along line 8-8 of FIG. 7

and including a portion of the base of the circuit breaker.

A three-pole molded-caseelectric circuit breaker without the latching means of this invention is disclosed in the abovementioned copending application. Those familiar with the art know that such a circuit breaker includes a base and a cover space-into three separate compartments each of which may contain an arcing and a pair of main stationary contacts, a

contact arm carrier, an arcing and a pair of main contact'arms gle toggle mechanism disposed in the center compartment and operable by a handle extending outwardly through the cover moves the three carriers.

FIG. I shows a circuit breaker 10 similar to that of the above-mentioned copending application, but including a In accordance with" this invention, a latch bracket 32 is secured to the carrier.24 in cooperative relationship with the latching device 12 by a pair of screws 34 (FIG. 7 g

The latching device 12 includes a mounting base 36 formed of insulating material and secured adjacent opposite opposite ends respectively to an outer wall 38 and. an intermediate 'wall 40 of the base 14 by a plurality off; screws 42, the walls 38 and 40 partially defining the com partment 22. A steel frame member 44, somewhat in the shapeof' a rectangular spiral having five consecutively joined planar sections, is secured to the base 36 in any suitable inanner, as by rivets (not shown) extending through the base 36 and respectively througha pair of bent over tab portions 440 and 44b of the fram e member. A generally U-shaped laminated 'niagnetizable core member 46 is provided with'two outer laminations 47 and 48 which extend beyond and are differently shaped from the other laminations so as to serve as stationary auxiliary frame members. The laminations or frame members 47 and 48 are secured to the inside of frame member 44 by a pair of pin members 53 and 54. i A generally straight laminated armature member 50 is provided with two generally L-shaped outer laminations 51 and 52 which serve as movable frame members. The armature member 50 is pivotally mounted by means of a pin 56 which extends through the laminations or frame members 51 and 52. I

The pin 56 is supported adjacent one end in the lamination or frame member 47, adjacent the other end in an extension of the frame member 44, and intermediately in the lamination or frame member 48.

The frame'members SI and 52 are provided respectively with bent over? tab portions 51a and 52a in which a. pair of screws 58 are respectively mounted. A' pair .of tension springs 60 form resilient connections respectively between the threaded end portions of the screws 58 and 'ap'air of bent over tab portions 47a and 48a respectively of the frame members 47'and 48. One end portion of each spring 60 is threaded on therespective screw 58, and a hookis provided at-th'e other end, the hook extending through-an aperture in the respective having interior partition walls generally dividing the enclosed latching device 12 constructed in accordance with this invention. The circuit breaker 10 includes a base 14, a cover 16, and an operating handle 18 extending through an aperture 19 in the cover 16 from a center compartment (not shown) and selectively movable into 0N and OFF positions indicated by suitable indicia on the cover. The handle'l8 operates a toggle mechanism (not shown) which drives a crossbar 20 formed of insulating material and extending across the center compartment into two opposite outer compartments, one of which is indicated at 22 in FIG. 1. A contact arm carrier 24 mounted for pivotal movement in the compartment 22 is secured to the crossbar 20 by means of a generally U-shaped bracket 26 secured in any suitable manner to the carrier 24 in embracing relationship with the crossbar. Similar carriers (not shown) are secured to the crossbar 20 in the other two compartments,

tab portion. The springs 60 bias the armature member 50 clockwise as viewed in FIG. 2; counterclockwise as viewed in FIG. 8.

An electric coil 62 is mounted in surrounding relationship with a leg portion of the core member 46 opposite the pivotal mounting of the armature member'50. The coil 62 is provided with a pair of lead wires 62a which mayextend to a remote control point for remote operation of the latching means 12. Energization of the coil 62 attracts the armature member 50, which then pivots against the bias of the springs 60 clockwise as viewed in FIG. 8; counterclockwise as viewed in FIG. 2.

A guide link 64 ispivotally mounted on the pin 56 and held axially therealong by a plurality of spacers 65 and shims 66 disposed between theframe member 48 and a portion of the frame member 44. A latch pin 68 is mounted for pivotal movement about the pin 56, being supported adjacent one end in the frame member 51, adjacent the other end in the guide link 64,- and intermediately in the frame member 52.

A shaft 70 is mounted in the frame member 44, being supported thereby at three places along its length. Pivotally mounted on the shaft 70 is a latch member 72 best shown in FIGS. 5 and 6. The latch member 72 is biased counterclockwise as viewed in FIG. 8 by a torsion spring 74 having one end portion held by the frame member 44 and the other end portion in bearing engagement with the latch member 72.

The latch member 72 includes a generally U-shaped portion havinga bight portion 72a connecting a pair of spaced, generally parallel leg portions 72b and 72c. The leg portion 72b is provided with an extension 72d extending generally perpendicular to the bight portion 72b and offset toward the leg portion 72c A further extension 72 is provided adjacent the extension 72e extends generally parallel to the bight portion 72a and is provided with a latchable surface portion 72f and a cam surface portion 72g. The latchable surface portion 72f is cooperable with the latch pin 68 in holding the latch member 72 in a latching position, as best shown in FIG. 8. The cam surface portion 72g moves the latch pin 68 out of the way temporarily against the bias of the springs 60 in the movement of the latch member 72 to a latching position.

The leg portion 7212 also has a latch hook extension 72h having a latching surface portion 72k cooperable with an inner surface of the latch bracket 32. as best shown in FIG. 8, to hold the contact arm carrier 24 and the other carriers connected to the crossbar in an OFF position.

The leg portion 72c has a cam extension 72m cooperable with an outer surface of the latch bracket 32, as the carrier 24 is moved to OFF position, in pivoting the latch member 72 to the latching position against the bias of the spring 74.

The portion 7211 has a hole'72p and the portion 720 has a hole 72q for the reception of the shaft 70.

When the carrier 24 is in latched, OFF position and the hantile 18 is in ON position, energization of the coil 62 attracts the armature member 50 toward the leg portion of the core member 46 within the coil, moving the latch pin 68 out of latching relationship with the latchable surface portion 72f of the latch member 72. The spring 74 then pivots the latch member 72 to move the latching surface portion 72k out of latching relationship with the latch bracket 32, whereupon the carrier 24 and the other carriers connected to the crossbar 20 move to the ON position, since the handle and operating mechanism are in ON position. The coil 62 may be deenergized as soon as the armature member 50 has moved.

While the device of this invention permits movement of the contact arm carriers to ON position by remote control, resetting of the carriers to latched, OFF position is accomplished by direct manual movement of the handle 18 first to OFF position and then back to a locked ON position. Movement of the carrier 24 to OFF position brings the outer surface -of the latch bracket 32 into engagement with the cam extension 72m and effects pivoting of the latch member 72 to bring the latch pin 68 back into latching relationship with the latchable surface portion 72f and to bring the latching surface,

portion 72k back into latching relationship with the latch bracket 32.

We claim:

1. A multipole electric circuit breaker comprising a molded case, a plurality of compartments in the case, a plurality of contact arm carriers disposed respectively in the compartments and tied together for operation as a unit, an operating handle disposed in one of the compartments and extending outwardly of the case, the handle being operatively connected to the contact arm carriers and movable to ON and OFF positions and the contact arm carriers being pivotable to corresponding ON and OFF positions by operation of the handle, and electrically releasable latching means in another of the compartments releasably connectable with the contact arm carrier therein for holding the contact arm carriers in OFF position while the handle is in ON position and operable while the handle is in ON position to release the contact arm carriers for movement to ON position,

2. A multipole electric circuit breaker as claimed in claim 1 wherein the latching means includes a latch bracket secured to a respective one of the contact arm carriers and pivotally mounted latch member having a latching surface portion cooperable with the latch bracket in holding the contact arm carriers in OFF position while the handle is in ON position.

3. A multipole electric circuit breaker as claimed in claim 2 wherein the latching means includes a movable latch pin and the latch member has a latchable surface portion cooperable with the latch pin in holding the latch member in a latching position with respect to the latch bracket.

4; A multipole electric circuit breaker as claimed in claim 3 wherein the latching means includes a magnetizable core member, an electric coil magnetically associated with the core member, and a pivotally mounted armature member attractable toward the core member upon energization of the coil, and the latch pin pivots with the armature member. 

1. A multipole electric circuit breaker comprising a molded case, a plurality of compartments in the case, a plurality of contact arm carriers disposed respectively in the compartments and tied together for operation as a unit, an operating handle disposed in one of the compartments and extending outwardly of the case, the handle being operatively connected to the contact arm carriers and movable to ON and OFF positions and the contact arm carriers being pivotable to corresponding ON and OFF positions by operation of the handle, and electrically releasable latching means in another of the compartments releasably connectable with the contact arm carrier therein for holding the contact arm carriers in OFF position while the handle is in ON position and operable while the handle is in ON position to release the contact arm carriers for movement to ON position,
 2. A multipole electric circuit breaker as claimed in claim 1 wherein the latching means includes a latch bracket secured to a respective one of the contact arm carriers and pivotally mounted latch member having a latching surface portion cooperable with the latch bracket in holding the contact arm carriers in OFF position while the handle is in ON position.
 3. A multipole electric circuit breaker as claimed in claim 2 wherein the latching means includes a movable latch pin and the latch member has a latchable surface portion cooperable with the latch pin in holding the latch member in a latching position with respect to the latch bracket.
 4. A multipole electric circuit breaker as claimed in claim 3 wherein the latching means includes a magnetizable core member, an electric coil magnetically associated with the core member, and a pivotally mounted armature member attractable toward the core member upon energization of the coil, and the latch pin pivots with the armature member. 